nuclear magnetic resonance

the selective absorption of electromagnetic radiation by an atomic nucleus in the presence of a strong, static, magnetic field: used in research and in medicine to monitor tissue metabolism and to distinguish between normal and abnormal cells.

nuclear magnetic resonance

noun

1.

a technique for determining the magnetic moments of nuclei by subjecting a substance to high-frequency radiation and a large magnetic field. The technique is used as a method of determining structure NMR See also electron spin resonance

Abbr. NMR The absorption of electromagnetic radiation of a specific frequency by an atomic nucleus that is placed in a strong magnetic field, used especially in spectroscopic studies of molecular structure and in medicine to measure rates of metabolism.

nuclear magnetic resonanceThe absorption of electromagnetic energy (typically radio waves) by the nuclei of atoms placed in a strong magnetic field. The nuclei of different atoms absorb unique frequencies of radiation depending on their environment, thus by observing which frequencies are absorbed by a sample placed in a strong magnetic field (and later emitted again, when the magnetic field is removed), it is possible to learn much about the sample's makeup and structure. Nuclear magnetic resonance has no known side effects on the human body, and is therefore used to analyze soft body tissues in magnetic resonance imaging (MRI).